The clinical management of inner ear diseases such as vertigo of Meniere's disease, sudden viral deafness, and autoimmune allergic inner ear disease remains a challenge in otolaryngology. Although some diseases can be treated with systemic medications, not all diseases and patients are responsive to this treatment. Furthermore, relatively high concentrations of the medication are required with systemic treatment, regardless of whether the medication is administered intramuscularly, intravenously, or orally. Finally, some medications have undesirable systemic effects.
Direct treatment of inner ear diseases is an alternative to systemic medications.
Currently, there are several procedures available to deliver medication to the inner ear. In one procedure, a physician injects medication into the middle ear over the round window area through the tympanic membrane. The patient is asked not to swallow and must remain relatively still in the supine position with the head turned both during the injection and for some time afterwards (at least 30 minutes) to allow the medication to diffuse through the round window. A tube could be placed in the ear drum to convey medication. As there is no pathway for evacuation of air as the medication is applied through the tube, it is difficult to get the medication to go into the middle ear. This is analogous to a situation in which one attempts to pour fluid into a container that has only one hole. If the medication does not get into the middle ear, it may flow down the eustachian tube or it may not get directly to the round window membrane. In fact, most medication is lost down the eustachian tube when the patient swallows. Another drawback to this procedure is the need for repeated doctor visits for injection of the medicament. As a result, this procedure is not very cost or time efficient.
One technique for direct treatment that has been developed uses a small gelatin sponge placed on the round window membrane. The physician then injects the medication directly onto the sponge. Like direct treatment with a tube, this procedure requires many office visits and medicament may be lost down the eustachian tube. Furthermore, the gelatin material that the sponge is made of may deteriorate.
Another recently developed technique utilizes an indwelling catheter that requires an operating room surgical procedure for implantation. A micro-pump can be attached to the catheter to deliver exact amounts of medication. Although this technique has had some clinical success, the catheter, micro-pump, surgical procedure, and subsequent hospitalization are very expensive.
As the discussion above illustrates, there is a need for an improved method and device for treating inner ear diseases.